Re: [Qemu-devel] [PATCH v4 2/2] loader: store FW CFG ROM files in RAM

2013-08-19 Thread Laszlo Ersek
On 08/19/13 16:26, Michael S. Tsirkin wrote: > ROM files that are put in FW CFG are copied to guest ram, by BIOS, but > they are not backed by RAM so they don't get migrated. > > Each time we change two bytes in such a ROM this breaks cross-version > migration: since we can migrate after BIOS has

Re: [Qemu-devel] [PATCH v4 2/2] loader: store FW CFG ROM files in RAM

2013-08-19 Thread Paolo Bonzini
Il 19/08/2013 19:40, Michael S. Tsirkin ha scritto: > On Mon, Aug 19, 2013 at 07:28:12PM +0200, Paolo Bonzini wrote: >> Il 19/08/2013 16:26, Michael S. Tsirkin ha scritto: >>> ROM files that are put in FW CFG are copied to guest ram, by BIOS, but >>> they are not backed by RAM so they don't get mig

Re: [Qemu-devel] [PATCH v4 2/2] loader: store FW CFG ROM files in RAM

2013-08-19 Thread Michael S. Tsirkin
On Mon, Aug 19, 2013 at 07:28:12PM +0200, Paolo Bonzini wrote: > Il 19/08/2013 16:26, Michael S. Tsirkin ha scritto: > > ROM files that are put in FW CFG are copied to guest ram, by BIOS, but > > they are not backed by RAM so they don't get migrated. > > > > Each time we change two bytes in such a

Re: [Qemu-devel] [PATCH v4 2/2] loader: store FW CFG ROM files in RAM

2013-08-19 Thread Paolo Bonzini
Il 19/08/2013 16:26, Michael S. Tsirkin ha scritto: > ROM files that are put in FW CFG are copied to guest ram, by BIOS, but > they are not backed by RAM so they don't get migrated. > > Each time we change two bytes in such a ROM this breaks cross-version > migration: since we can migrate after BI

[Qemu-devel] [PATCH v4 2/2] loader: store FW CFG ROM files in RAM

2013-08-19 Thread Michael S. Tsirkin
ROM files that are put in FW CFG are copied to guest ram, by BIOS, but they are not backed by RAM so they don't get migrated. Each time we change two bytes in such a ROM this breaks cross-version migration: since we can migrate after BIOS has read the first byte but before it has read the second o